The World Health Report 2006 identified 57 countries world-wide whose health
worker to population density fell below a
critical threshold of 2.3 per 1,000 population. This meant that below this
critical threshold, a country could not provide the
basic health services to its population, defined here as 80% immunization
coverage and 80% skilled birth attendance at
delivery. Of the 57 countries, 36 are located in Africa.This article reviews the
progress countries have made in addressing
their health workforce crisis. It cites 3 of the most recent global studies and
the indicators used to measure progress. It
also features the experiences of 8 countries, namely Malawi, Peru, Ethiopia,
Brazil, Thailand, Philippines, Zambia, Mali.
Their situations provide a diverse picture of country efforts, challenges, and
successes. The article asks the question of
whether the target of 25% reduction in the number of crisis countries can be
achieved by 2015. This was a goal set by the
World Health Assembly in 2008. While the authors wish to remain optimistic about
the striving towards this target, their
optimism must be matched by an adequate level of investment in countries on HRH
development. The next four years
will show how much will really be achieved.

In January 2011, the Second Global Forum on Human
Resources for Health was held in Bangkok, Thailand.
Entitled "Reviewing Progress, Renewing Commitment",
it convened over 1,000 participants of the global HRH
community three years after the first forum in Kampala,
Uganda.

At the final plenary session, a note of impatience was
struck. Delegates made the recommendation that the
third global HRH meeting should not be convened unless
there was clear evidence of progress in addressing the
HRH crisis in countries. Delegates urged that stronger
leadership and more drastic measures be undertaken to
solve the crisis (1).

Indeed, it had been five years since the World Health
Report 2006 had identified 57 countries to be in HRH
crisis. This meant that they fell below a critical threshold
of 2.3 health workers per 1,000 population. Countries
below this threshold had difficulty ensuring 80%
attendance of a skilled birth attendant at delivery as well
as 80% coverage for child immunizations (2).

But even prior to this report, in May 2004, the World
Health Assembly had already called for action to mitigate
the negative effects of the international migration of
health workers through resolution WHA57.19 (3). And in
December of that year, the Joint Learning Initiative which
brought together various experts and advocates in the
field, issued a report calling for global attention to the
HRH crisis in countries (4).

In May 2010, the 63rd World Health Assembly through
resolution WHA63.16 adopted the WHO Code of Practice
for the International Recruitment of Health Personnel (5).
The work on Code development had been at a standstill
until the Kampala Forum ignited progress. The adoption
of the WHO Code was an international milestone. WHO
Director-General Margaret Chan referred to it as "a gift
to public health" (6). But as this article will show, WHA
resolutions and the Code only represent the vision and
aspiration of Ministers and planners in high places.
Turning these into reality in countries is where the true
victory lies.

To date, none of the 57 countries in HRH crisis have
risen out of it.

This article will review some of the work in countries
and will provide some observations of where global and
national efforts are making headway or falling short.

ADDRESSING THE HRH CRISIS IN COUNTRIES.
SETTING OUR TARGETS.

The global community has been good at setting targets.
The MDGs are a case in point. There have been other
resolutions calling for urgent action on the HRH crisis. In
May 2006, WHA59.23 called for a rapid scaling up health
workforce production particularly in crisis countries (7).

Also, in May 21, 2007, WHA60.11 endorsed the
Medium-Term Strategic Plan 2008-2013 (8). One of the
targets in this 5-year plan was the "reduction of 25% in
the number of countries facing critical health workforce
shortages, and an increase in the equitable distribution
of the workforce" (9). This target envisioned that at least
14 countries would lift themselves out of their HRH crisis
by 2013.

In declaring this target, the MTSP summarized the
obstacles that needed to be overcome. These included:

1) limited production capacity in many developing
countries as a result of years of underinvestment in health
education institutions; 2) the geographical imbalance
in the distribution of health workers with abundance in
urban areas and a shortage in remote and rural areas; 3)
the migration from poor countries to developed countries
(10).

In order to develop an effective health workforce for
any specific context, a country had to solve a number
of issues: 1) effective planning which encompassed
many sectors, including health, education, and finance
as well as the public and private sectors; 2) developing a
strong knowledge base as a starting point for planning;
3) sustaining investments in order to build capacity in a
country's its key public and private institutions over short
term and the long term and 4) the building of a critical
mass of leaders and managers to guide the process.

Having been part of the technical team that proposed
this target, the author (MMD) recalls that the target was
set with great optimism for the future. The optimism
stemmed from the increasing activities in countries to
address health workforce issues, and what seemed to
be a growing momentum in the initiatives to strengthen
health systems. A Global Health Workforce Alliance
(GHWA) had been established in 2006 to strengthen
global advocacy. Representatives of development
agencies and international institutions were included
among the members of the GHWA Board and there was
great enthusiasm for providing support to countries for
their HRH development) (11).

However, MTSP 2008-2013 also made assumptions and
identified risks in the long journey towards the targets.
Two assumptions were notable: 1) that governance and
strategic planning would improve across all government
sectors including health; 2) that changes would be
made in the financing channels and modus operandi
of external partners, in line with the Paris Declaration
on Aid Effectiveness. Two risks needed to be offset: 1)
the insufficiency of international and national investment
to meet the increasing demand in the area of health
workforce development and 2) the global market forces
favoring migration from countries already lacking
sufficient health workers (10).

How have countries fared since MTSP 2008-2013 was
adopted? There have been three surveys done to assess
the progress in countries on HRH development, the third
being the interim assessment of MTSP 2008-2013. In
sum, these surveys give us an idea of what has actually
been undertaken by countries in HRH development (1
survey) and also how countries perceive their efforts (2
surveys).

MEASURING PROGRESS IN COUNTRIES

WHO desk review (12). To get an overall pictures of where
efforts were being placed, WHO worked with the Royal
Tropical Institute, Amsterdam to undertake a desk review
between June and December 2009 to survey practices,
policies and plans in the 57 crisis countries. The desk
review inventoried secondary data from various sources,
including MoH documents, reports to donors like GAVI
and the Global Fund. While there were no baselines, the
review did provide a picture of HRH efforts in countries
at that point in time.

National planning for HRH and costing of HRH plans
-- 45 (79%) out of 57 countries had developed HRH
plans. Of these 45, 32 (71%) had an implementation
budget but only 25 (55%) of the plans were being
implemented.

The top 5 issues highlighted in the HRH plans with
strategies to address them were: 1) pre-service
education 2) in-service education 3) educational targets
referring to the number of health workers to be trained 4)
career development and 5) incentives, usually related to
payment, housing and transport.

The desk review showed that 51 (89%) out of the 57
countries had an HRH department in the ministry of
health. The actual functioning of these departments and
their contribution to overall country HRH planning could
not be ascertained.

Finally, 14 (25%) of the 57 countries had a national
HRH observatory which acted as a mechanism for
collecting and analyzing data on HRH as well as
convening stakeholders to review this information to
set policy.

Global Health Workforce Alliance survey (13). In
preparation for the Second Global Forum on HRH
in Bangkok, a survey was undertaken by the Global
Health Workforce Alliance in July 2010 to inquire about
the progress on the Agenda for Global Action set forth
in Kampala. Focal persons in the ministries of health
were asked to fill in a questionnaire online or by email.
Responses were gathered for 51 out of the 57 countries
surveyed.

The scores provided some idea of how respondents
perceived the progress of HRH work in the crisis
countries but limitations of the methodology preclude
any validation of the actual situation in countries. The
limitations included: the lack of baseline information,
the reliance on self-reported results, and the limitations
of the questionnaire itself. Thus, while a country may
have an HRH plan, the survey does not reveal its
content or quality or how well it is being implemented.
Similarly, the existence of an observatory does not
assure data quality nor its level of functionality. And
responses on investment say little about what it is for
and how much.

Medium-Term Strategic Plan 20082013 Interim
Assessment (14). The third survey was conducted
from November 2010 to March 2011. While this survey
polled countries on the 11 technical strategic objectives
covering the totality of WHO's diverse concerns, it
provided specific information of how countries viewed the
progress of work on HRH. These 11 strategic objectives
covered areas including the communicable diseases,
chronic noncommunicable diseases, emergencies and
disasters, social and economic determinants of health to
name a few. HRH was included in the strategic objective
involving health systems and services.

A selected national focal point coordinated the
completion of the questionnaire within a country. A
total of 105 countries responded out of 193 for a 54%
response rate. Responses were classified along a
5-point scale where 1 = significant regression; 2 = some
regression; 3 = no change; 4 = some progress; and 5 =
significant progress. On the target "reduction in critical
health workforce shortages and an increase in the
equitable distribution of the workforce", the composite
score was 3.68

The survey also asked: "Which system components would
you consider to be the priority for further development
from now until the end of 2013?" The responses were:
health financing 20%; health workforce 20%; policy
framework 17%; service delivery 16%; leadership and
governance 14%; health information systems 11%;
medical products and technologies 2%.

What can we learn from these three studies? At best, we
have objective information of the presence of plans and
planning mechanisms in a good number of HRH crisis
countries. We also have subjective information about
how countries perceive the progress of efforts based on
the responses of a selected focal point. The responses
suggest that work is ongoing in strengthening HRH
particularly with regards the development of country
plans. There is some information on the direction that
the plans are taking, for example towards strengthening
pre-service education. Furthermore, the studies inform
us that 20% of countries consider HRH to be a priority
over the next couple of years but also that there are
a variety of other competing concerns that demand
attention. The studies do not tell us if investments
follow the planning and whether these are adequate
and realistic.

A better understanding of progress in countries can be
acquired by looking at the situation in specific countries
themselves. The following eight have been selected
because they help illustrate a particular point.

Malawi -- to show success of a 5-year emergency
programme to rescue a failing national health workforce
(2005-2010)

Peru -- to show how the reform of the mandatory rural
service system resulted in an increase in HRH density
and contributed to a decrease in maternal mortality over
a 3-year period (2006-2009)

Ethiopia -- to show the gains from a governmentled
health extension worker programme which has
demonstrated impressive health outcomes after only 5
years (2005-2010)

Brazil -- to show a sustained effort since the 1980s to
build a critical mass of family health teams which have
improved services and health outcomes in remote rural
underserved areas

Thailand -- to show the success of a multi-sectoral and
multi-disciplinary effort which has been ongoing since
the 1970s to ensure equity in the distribution of health
workers and health services throughout the country

Philippines -- to show the outcomes and challenges
of a private sector, market driven model in terms of
responding to domestic need and international demand
for nurses

Zambia -- to show how early efforts in providing incentive
schemes for doctors have increased their retention in
the rural areas

Mali -- to show how efforts of an NGO have demonstrated
effective retention of physicians over a period of 15
years.

COUNTRY EXAMPLES

MALAWI

What does it take to get a country out of HRH crisis?
Malawi is one of the 57 HRH crisis countries. From 2004-
2009, government and international partners collaborated
on an emergency HR response to lift the country out of
HRH crisis. This programme was evaluated in 2010. The
findings were as follows (15).

The programme deployed a strategy to improve the
incentives for recruitment and retention of Malawian
healthcare staff, expand domestic training capacity by
over 50% overall, and utilize international volunteer
doctors and nurse tutors to fill critical posts while more
Malawians were being trained.

The interventions were huge and the results were
impressive. Of the 5-year direct investment of USD 95.6M
about 36% went into a 52% taxed salary top-up for 11
professional cadres. As a result, health worker numbers
increased significantly. Physicians in particular grew from
43 in 2004 to 265 in 2009, representing a 516% increase;
nurses who historically had huge losses to out-migration
posted a 39% increase in the same period.

As training capacity increased for various cadres and
retention in their posts improved with financial and other
incentives, the health worker to population density rose
from 0.87 per thousand population in 2004 to 1.44 per
thousand by 2009, representing a 83% increase. This
increase outpaced population growth of 10% over the
same period thereby showing a net gain. However, the new
levels of health worker density still fell below the African
region average (1.91 per 1,000) and the world average
(6.23 per 1,000) showing how deep a crisis Malawi was in.

The gains in HRH density produced a tangible impact on
health services -- 49% increase in out-patient services;
7% increase in ante-natal care; 15% increase in safe
deliveries; 10% increase in child immunizations and an
18% increase in the provision of nevirapine to prevent
maternal-to-child transmission of HIV. All these services
were estimated to have saved 13,187 lives.

Looking towards the future, 3 costed scenarios have been
forecast. The first scenario which simply maintains the
gains over the last 6 years will mean investments of USD
43.5M over the next 5 years. The second scenario which
posts an additional 9-13% increase in staff numbers will
need USD 59.4M over the next 5 years. While the third
scenario which shows a 5% loss of workers over the
next 5 years will cost USD 42.1M.

PERU

Peru is one of the few Latin-American countries which
was designated in the World Health Report 2006 as
being in HRH crisis. Over the past decade and more,
the country lost more than 1,400 medical doctors to
migration every year (16). But the country took a number of
decisive steps at addressing the crisis at various levels.
At the national level, services dealing with personnel
administration and human resources policy, planning
and information development were put under a unified
directorate. At the same time, an HRH Observatory was
integrated to increase the quantity and quality of HRH
information for decision-making and policy development.
Thus stewardship of the entire HR development system
was strengthened.

The concept of Family Health Teams was developed
with far-reaching reforms at the level of curricula
development and team organization with distinct tasks
assigned to doctors, nurses and other team members.
One of the promising interventions was strengthening
the mandatory service for newly graduated staff
(SERUM) who have to serve rural and marginalized
populations. Some measurable results have already
been demonstrated through a reduction in maternal
mortality in some parts of the country as a result of the
reorientation of the programme.

As can be seen clearly from the graph, increase in HRH
density led to visible results in the reduction of maternal
mortality in two provinces: Apurimac: minus 22% and
Ayacucho: minus 65%) whereas it remained stable in
Huancavelica where HR density only saw a comparatively
small increase. This study shows that a reorientation of
the HR distribution system with a few incentives can
impact the health outcomes of a country rapidly even
when resources do not increase significantly (17).

ETHIOPIA

Ethiopia has produced 32,000 health extension workers
since 2005 passing them through a 1 year course before
deployment in remote health posts. These workers were
supervised by a clinical officer who was based in a health
center.

In 2009, an impact evaluation of the health extension
programme was conducted (18) . The study which covered
3095 households from both programme and nonprogramme
villages showed that programme areas had
a significantly higher proportion of children vaccinated
against tuberculosis, polio, diphtheria-pertussis-tetanus,
and measles. Use of insecticide-treated bednets for
malaria protection were also significantly higher in
programme villages.

Where the programme has shown no impact so far is
in prenatal and postnatal care services. It appears that
pregnant mothers still prefer to go to their grandmothers
and other traditional birth attendants rather than entrust
themselves to the care of the health extension workers.
Health extension workers have the opportunity to go for
further training and eventually become family doctors after
a certain number of years. Five years since the start of
this programme, less than 1% of these health extension
workers have dropped out (personal communication,
Gebrekidan Mesfin, WHO country office, Ethiopia).

BRAZIL

In the late 1980s it was recognized that Brazil's system
of specialized, urban-centered, hospital-based medical
care was failing to meet the needs of the many families
who could not afford, or could not access, services. At
the same time, a shortage of vocational schools had led
to more than 200,000 workers taking on nursing and
technical functions, without the qualifications required by
law. In 1988, the government decentralized the national
health system with the goal of achieving universal access
to primary health care for all citizens. To meet the human
resource needs of the new system, the Ministry of Health
adopted a strategy of training family health teams to
provide care for the country's entire population (The
Family Health Program). Each team, which looks after
2000 to 3500 families, is composed of one physician,
one nurse and up to six health aides, such as auxiliary
nurses, community health workers and other technical
support workers (19).

The government aimed to ultimately establish 40,000
family health teams throughout the country by 2010. To
achieve this, the government budgeted more than $700
million between 2000 and 2009. By 2007, approximately
25,000 health teams covered about 60% of the Brazilian
population.

In an evaluation, the municipalities that were eight years
into the programme showed impressive reduction in
mortality rates for infants, children under-5 years, adults
15 to 59 years, and persons over 59 years. Compared
to the national averages (1993), the reduced rates for
the above mentioned age groups were 20%, 25%, 8.5%
and 2.7% (20).

In addition, the evaluation found impact on human capital,
expressed as returns on improved labor, children's
education and fertility. After eight years of exposure to
the programme, the communities experience a 6.8%
increase in the labor supply of adults, a 4.5% rise in the
school enrolment of children up to age 17 and a 4.6%
reduction in the probability that women aged between
18 and 55 give birth within 21 months after their previous
pregnancy (20).

THAILAND

Thailand has one of the longest experiences with
addressing the challenge of rural retention. For the last 40
years, Thailand has put in place an integrated approach to
address this issue, which included recruitment of students
with rural background, and training them closer to the
communities, a model called "local training and home-town
placement" of nurses and doctors. In addition, mandatory
government bonding was initiated in the 1970s and both
financial and non-financial incentives were provided for
doctors in rural practice. Furthermore the social movement
of the rural doctors association strongly advocated for the
importance of rural health and other issues of public health
importance. All these developments combined to reduce
the difference in the density of doctors between Bangkok
and the poorest north-east region from 21 times in 1979
to 9.4 times in 2000 (21). Despite these efforts, retention of
doctors in rural areas beyond the bonding period remains
a challenge, as new developments such as medical
tourism attract physicians towards urban practice and
specialization training.

PHILIPPINES

The Philippines has a very strong private sector,
market-driven educational system which has produced
thousands of nurses every year. Production comes from
517 nursing schools many of which were set up to respond
to the local demand for nursing education. In 2007
alone, almost 60,000 licensed nurses were produced.
The challenges the country faces are several fold: first
is regulating the excessive production of nurses and to
ensure the quality of the graduates; second is providing
enough jobs for them, whether locally or overseas; third
is attracting them to work in the remote and rural areas,
and fourth is establishing mechanisms for experienced
nurses who have worked abroad to return and continue
their careers when they return.

Overseas employment has invariably been the
reason why young students turn to nursing. In 2000,
an estimated 163, 756 Filipino nurses were working
abroad, of which 110, 774 (67%) were working in OECD
countries. In 2000, 7683 nurses emigrated and by 2009,
almost twice the number (13,014) left the country for
overseas employment. Reasons for migration have been
economic. A nurse earns USD 5000 a month in the US or
the UK, almost 50 to 100 times what she would earn in
Manila (USD 58-115 per month) (22).

In 2008, in response to the excessive number of
unemployed nurses, the government launched the NARS
program (Nurses Assigned in Rural Service). The goals
of the program were to address the unemployment as
well as provide nurses to the poorest municipalities of the
country. To start, 1,000 poor areas were identified where
5 selected nurses would be deployed for a period of year.
This period would serve as a time of practical training
in the field after which the opportunity for employment
could follow. The program pays the nurse-trainee a
monthly salary of 8,000 pesos (USD 180). Supervision
of the nurses is undertaken by the Department of Health.
The evaluation of the program is ongoing (23).

In 2009, an estimated 400 000 licensed nurses in the
Philippines were not employed in the nursing profession
(22).

ZAMBIA

In 2003, to address the issue of shortages and
maldistribution of health workers in underserved areas,
in 2003 the Government of the Republic of Zambia in
partnership with the Royal Netherlands Government
started to pilot the Zambian Health Workers Retention
Scheme (ZHWRS) for health professionals. The scheme
was conceived initially to replace the Dutch doctors
working under the bilateral agreement between Zambia
and the Netherlands. Funding for this scheme came
at first from the government of the Netherlands. The
scheme provides financial incentives in the form of a
hardship allowance, school fees, loans facility for a car
or a house, and assistance with post-graduate training
at the end of the three-year contract. A mid-term review
in 2005 and subsequent assessment of the pilot showed
that 88 doctors were retained for the 3 year contract
period, and 65% renewed for a second 3 year term.
As a result, many districts have now been staffed with
a Zambian doctor for the first time ever. The average
monthly cost of the scheme per doctor is between 500
 550 (US$652 to 717) (24). The scheme has now been
expanded to include other types of health workers, and
additional donors are supporting the scheme, through
the common basket financing mechanism, set up by the
Ministry of Health (25).

MALI

More than 100 doctors have been supported to set up a
practice in rural and remote areas, through a programme
piloted by the NGO, Sante Sud, France during a period
of more than 15 years. The programme targeted young
unemployed urban doctors. It offered an installation kit
containing, for example, medical equipment, solar panels
and sometimes even a motorbike, Specific training in
community medicine and membership in a professional
association helped reduce feelings of isolation and
strengthen members' capacity to engage in collective
bargaining. These doctors were paid by a combination
of public-private partnership and community-based
contracts, facilitated by the country's decentralization
policy. An evaluation of this programme conducted by
WHO in 2008 found that on average, these physicians
stayed longer in their posts (4.5 years) compared with
doctors who were not supported by this package (2.5
years). Some doctors stayed for more than 10 years
(26). One of these young doctors was recently honored
during the Second Global Forum on Human Resources
for Health with the Special Recognition Award for his
commitment to serve his rural community.

WHAT LESSONS CAN WE DERIVE WHICH
WILL HELP IN ELIMINATING THE CRISIS IN
COUNTRIES.

The lessons from the countries show that with good
planning, the correct strategies, and enough resources,
it is possible to reverse the HRH crisis in a country over
a few years. This is shown by the examples of Malawi,
Peru, and Ethiopia. The lessons from Brazil and Thailand
show what needs to be done so that a country does not
get into a crisis in the first place -- political will, adequate
investments, and effective management over the long
term. The lesson of the Philippines shows that a large
production of health workers will not necessarily provide
services to the underserved population unless there
are effective strategies to attract and maintain health
workers in rural areas. In this regard, the lessons of Mali
and Zambia are encouraging as these countries show
success in present efforts to attract and retain doctors in
the rural areas.

To address the HRH crisis in any country, the fundamentals
of the HRH work cycle remain (see figure 3).

1) the entry circle. Ensure the adequate production of
health workers in the numbers and types needed by the
population. Pay attention to the quality of education of
health workers and to the relevance of health worker
education to the needs of the population. The challenges
in this area have to do with linking education with practice
and the jobs available when students graduate. The
education and labor market for health workers are not
easily regulated and imbalances between the supply of
graduates and the demand for them often persist.

2) the circle of the existing health workforce. Jobs
which provide health workers with a sense of purpose
and service, adequate compensation for livelihood,
challenges to surmount, a career track to pursue,
recognition for their work, and peers and mentors to
emulate will attract and retain health workers. All these
should be taken into consideration in designing the jobs
and opportunities particularly in remote and rural areas. In
this regard, comprehensive strategies are more effective
than single interventions. Sustainability is crucial and
time for steady capability building is necessary.

To address the huge challenge of attracting and
retaining health workers in rural areas, WHO issued
in 2010 global policy recommendations for improving
access to competent health workers in remote and
rural areas (27). These guidelines were based on the
varied experiences of countries as well as a thorough
and systematic process of reviewing the evidence.
WHO is now working with partners to implement these
guidelines in countries.

3) the circle of exit. Health workers can be lost for
various reasons including to retirement, illness, death
and migration. All these factors can be managed and
planned for to some extent. The adoption of the WHO
Code of Practice for the International Recruitment of
health personnel is not only an ethical code which
discourages recruitment from countries in HRH crisis.
It is also a guide towards addressing the fundamentals
of production and retention and health workers. But in
itself, the WHO Code is not a panacea.

The effective governance of HRH development is critical
for keeping the work cycle in fine balance. Therefore,
persons who are competent to plan, and manage are
needed in countries -- in government, educational
institutions, and health service facilities. Furthermore,
organizing data for planning and policymaking is a
priority. In poor countries where domestic resources
are inadequate to provide appropriate investments, the
international donor community needs to provide effective
and sustained support (28).

CONCLUSION

This article has shown progress in global and country
efforts over the last five to seven years. It has presented
selected countries whose examples are instructive in
terms of tackling HRH challenges. These countries
have made remarkable strides towards addressing their
health workforce shortages and imbalances. Continuing
documentation, evaluation of experiences and sharing
of these lessons can act as a stimulus to all countries to
learn from these and other examples.

Concluding thoughts: Global targets help set the pace, but
internal processes in countries largely determine whether
these targets can be reached. Countries progress at their
own pace. The presence of investments influence the
pace of progress. For the poorest countries which lack the
resources to change things on their own, adequate and
sustained resources from partners and external agencies
coupled with political will and effective management
internally, are necessary to achieve real progress.

Many challenges remain. In the face of them, should we
give up on the idea of a 25% reduction of countries in
HRH crisis by 2015? Perhaps not yet -- as some countries
have shown that much can be achieved in a few years.
Also, in the 64th World Health Assembly in May 2011,
Member States adopted resolution WHA64.6 on health
workforce strengthening (29). The resolution affirms the
priority that Member States put on human resources for
health. This allows us to be optimistic. Let us see what
the ongoing efforts in HRH development will bring in the
next four years.

Author Contributions

All authors have participated in the conception, drafting
and critical review of the manuscript, and have approved
the final version of the article.